Hydrostatic bearing support for a work tool

Abstract

A hydrostatic bearing support for a work tool has an inner stationary member with circumferentially disposed hydrostatic bearing areas which when pressurized, radially support an outer constant thickness cylindrical sleeve. Axial bearing support for the outer sleeve is provided by annular hydrostatic thrust bearing areas disposed at each end of the stationary member and cooperating with end caps which are secured to the outer sleeve. All of the liquid passages for directing pressurized liquid to the bearing members are formed within the stationary member.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A support spindle for a rotary tool comprising: a stationary shaft having an enlarged central cylindrical portion, cylindrical suppport means adjacent each end of said enlarged cylindrical portion and cooperating with said central cylindrical portion to form an annular end surface on each end of said central cylindrical portion, a pair of spaced recesses formed in the outer surface of said central cylindrical portion, a return recess formed in said central cylindrical portion intermediate the spaced recesses; inlet liquid passage means concentric with and extending coaxially through one of said cylindrical support means and also being coaxial with and extending into said central cylindrical portion a distance beyond said return recess; feed passage means for communicating liquid from said inlet passage means to both of said spaced recesses and to both of said annular end surfaces of said central cylindrical portion; outlet luquid passage means concentric with and extending coaxially through the other of said cylindrical support means and also being coaxial with and extending into said central cylindrical portion a distance less than said inlet passage means extends into said central cylindrical portion; return passage means for providing liquid communication between said annular end surfaces, said return recess and said outlet liquid passage means; a cylindrical sleeve rotatably mounted on said central cylindrical portion and cooperating with said spaced recesses to provide a pair of radial support hydrostatic bearings; a pair of end cap means secured to said cylindrical sleeve and enclosing said annular end surfaces and cooperating therewith to provide a thrust chamber at each end of said central cylindrical portion; annular thrust bearing means in each of said thrust chambers in liquid communication with said feed passage means and providing controlled liquid communication with said return passage means and cooperating with said end cap means to provide a pair of hydrostatic thrust bearings; a work tool secured to said cylindrical sleeve intermediate said end cap means for rotation with said cylindrical sleeve and said end cap means; means supplying pressurized liquid to said inlet passage means; and means for rotating said cylindrical sleeve relative to said stationary shaft. 
     
     
       2. A support spindle for a rotary tool comprising: a stationary shaft having an enlarged central cylindrical portion, cylindrical support means adjacent each end of said enlarged central cylindrical portion and cooperating with said central cylindrical portion to form an annular end surface on each end of said central cylindrical portion, a pair of spaced recesses formed in the outer surface of said central cylindrical portion, a return recess formed in said central cylindrical portion intermediate the spaced recesses; inlet liquid passage means concentric with and extending coaxially through one of said cylindrical support means and also being coaxial with and extending into said central cylindrical portion a distance beyond said return recess; feed passage means for communicating liquid from said inlet passage means to both of said spaced recesses and to both of said annular end surfaces of said central cylindrical portion; outlet liquid passage means concentric with and extending coaxially through the other of said cylindrical support means and also being coaxial with and extending into said central cylindrical portion a distance less than said inlet passage means extends into said central cylindrical portion; return passage means for providing liquid communication between said annular end surfaces, said return recess and said outlet liquid passage means; a cylindrical sleeve rotatably mounted on said central cylindrical portion having a constant thickness for the length of said enlarged central cylindrical portion and cooperating with said spaced recesses to provide a pair of radial support hydrostatic bearings; a pair of end cap means secured to said cylindrical sleeve and enclosing said annular end surfaces and cooperating therewith to provide a thrust chamber at each end of said central cylindrical portion; annular thrust bearing means in each of said thrust chambers in liquid communication with said feed passage means and providing controlled liquid communication with said return passage means and cooperating with said end cap means to provide a pair of hydrostatic thrust bearings; a work tool secured to said cylindrical sleeve intermediate said end cap means for rotation with said cylindrical sleeve and said end cap means; means supplying pressurized liquid to said inlet passage means; and means for rotating said cylindrical sleeve relative to said stationary shaft.